June, '19] SCIENTIFIC NOTES 269 



Scientific Notes 



Notes on Some Insect Pests of Costa Rica. During the latter part of February 

 and March of this year, while in Costa Rica for a vacation, a few observations were 

 made of the insect pests of that country. As the most serious of the pests do not as 

 yet occur in the United States, a few notes on them will be of more than casual 

 interest. 



The most important "find" was, no doubt, the "mosca prieta" or spiny citrus 

 whitefly {Aleurocanthus woglumi Ashby). It was very abundant on citrus of various 

 species at Limon and at all the stations of the Northern Railroad as far as Peralta. 

 At Cartago, at an elevation about one mile, it was not found. The degree of infesta- 

 tion was worse than it is in the Canal Zone. The trees were so heavily infested as 

 to be readily noticeable from the car windows. This whitefly occurs probably all 

 through Central America and tropical South America, particularly along the Atlantic 

 seaboard. From questions asked of the customs and port authorities, and from actual 

 observations, it would appear that this insect gained access to Costa Rica from small 

 sailing vessels coming from San Andres and other islands of the Caribbean. It seems 

 to be an inborn custom of the islanders to carry potted plants wherever they go. 

 Thus far fifty-two hosts, representing twentj^-six families of plants, have been recorded 

 for A. woglumi, among them being the various species of citrus, mango, star-apple, 

 cashew apple (maraiion), papaya, chirimoya, mamei, plantain, and coffee. 



The purple scale, Lepidosaphes beckii Newm., and sooty mould were extremely 

 abundant on both leaves and fruit of citrus. 



Another bad pest was the Hawaiian sugar-cane borer, Rhabdocnemis obscurus 

 Bois. It was exceedingly abundant at Zent, C. R., in banana stumps and cuttings. 

 As many as forty adults were taken out of a small piece of stalk about a foot long. 

 Dr. W. D. Pierce, in his Manual of Dangerous Insects, cites the following hosts for 

 this weevil: banana, sugar-cane, cocoanut, sago palm, royal palm, wine palm, and 

 papyrus. The important observation here was a few adults were found crawling on 

 the leaves of banana, showing that this serious pest can very easily be introduced 

 into the United States among the banana leaves used as packing for fruit on boats 

 calhng at New Orleans. 



At Limon, and awaiting boats for shipment to the United States, were about a 

 hundred flat cars loaded with Balsa logs, and, from data obtained, these were here 

 from one to four weeks. Under the bark of these logs were found a number of lepi- 

 dopterous larva; and pupa;. The great majority of the logs were infested with 

 several species of borers, specimens of which have been sent to the Bureau of Ento- 

 mology for identification. These borers were very active and abundant. As the 

 determinations are lacking at present writing, it is impossible to say whether they 

 are already present in the United States. However, the degree of infestation and 

 the ease with which such logs can enter the United States, makes the introduction 

 of such pests a certainty, and it is time to paj' attention to the possibilities of this 

 source of danger. Otherwise many new and dangerous pests will unquestionably be 

 added to our already large list of insect-immigrants. 



James Zetek, Ancon, Canal Zom\ 



A Source of Confusion in the Diagnosis of Nosema apis in Adult Bees. In March, 

 1917, the writer received for diagnosis from Cabarrus County, North Carolina (Sam- 

 ples Nos. 5324 and 532.5), a .sample of dead bees and two l>rood frames containing 

 honey, pollen and a few dead bees with heads in cells. The.se frames were from the 

 colony from which the dead l)ees had been taken, the colony having shown marked 

 syujptoms of dysentery earlier in the spa-^^on with many bees dying. .Microi^copic 

 examination of the large intestines from .•^mcnil of the dead bees macerated in salt 



